1. Field of the Invention
The invention relates to a wireless control method, more particularly to a method of wirelessly controlling a sewing machine.
2. Description of the Related Art
Control of an internal motor unit of a conventional sewing machine is usually conducted through a pedal-type controller. The rotation speed of the internal motor unit of the sewing machine is varied according to extend of treading action on a pedal of the controller.
When the aforesaid conventional sewing machine is in use, a machine body thereof is usually placed on top of a table, whereas the controller is placed on the ground to permit treading on the same. Therefore, since signal transmission between the controller and the machine body is conducted in a wired manner, a signal cord is required to extend from the top of the table to the ground, thereby resulting in some inconvenience.
To overcome the aforesaid drawback, it has been proposed heretofore to use a wireless mode of transmission between the controller and the machine body. To this end, a transmitter and a receiver are respectively stored with a preset security code therein, and are respectively provided in the controller and the machine body such that the controller converts user treading action into wireless control signals for subsequent transmission by the transmitter to the receiver in the machine body, thereby permitting control of the operation of the motor unit in the machine body.
It is noted that the security code stored in the receiver must match that stored in the transmitter prior to delivery. Hence, the machine body cannot cooperate with other controllers when the original controller malfunctions, thereby resulting in inconvenience during repair.
In such wireless signal transmission between the controller and the machine body, noise interference cannot not be avoided such that a high reliability of the wireless signal transmission cannot be ensured.
Furthermore, the space in the machine body of a conventional sewing machine is fully utilized. Hence, it is not possible to upgrade older sewing machines, which do not allow installation of the receiver inside the machine body, for wireless signal transmission purposes.